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Finding the Fourth Proportional to 285.45, 393.81 and 201.55

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Solution

The fourth proportional to 285.45, 393.81 and 201.55 is: 278.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.45 : 393.81 = 201.55 : x
  2. Step 2: Convert to fraction form
    285.45/393.81 = 201.55/x
  3. Step 3: Cross multiply
    285.45x = 393.81 × 201.55
  4. Step 4: Simplify right side
    285.45x = 79,370.92
  5. Step 5: Solve for x
    x = 79,370.92/285.45
  6. Step 6: Final answer
    x = 278.05

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.